'\" et
.TH LOCALE "1P" 2017 "IEEE/The Open Group" "POSIX Programmer's Manual"
.\"
.SH PROLOG
This manual page is part of the POSIX Programmer's Manual.
The Linux implementation of this interface may differ (consult
the corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
.\"
.SH NAME
locale
\(em get locale-specific information
.SH SYNOPSIS
.LP
.nf
locale \fB[\fR-a|-m\fB]\fR
.P
locale \fB[\fR-ck\fB] \fIname\fR...
.fi
.SH DESCRIPTION
The
.IR locale
utility shall write information about the current locale environment,
or all public locales, to the standard output. For the purposes of
this section, a
.IR "public locale"
is one provided by the implementation that is accessible to the
application.
.P
When
.IR locale
is invoked without any arguments, it shall summarize the current locale
environment for each locale category as determined by the settings of
the environment variables defined in the Base Definitions volume of POSIX.1\(hy2017,
.IR "Chapter 7" ", " "Locale".
.P
When invoked with operands, it shall write values that have been
assigned to the keywords in the locale categories, as follows:
.IP " *" 4
Specifying a keyword name shall select the named keyword and the
category containing that keyword.
.IP " *" 4
Specifying a category name shall select the named category and all
keywords in that category.
.SH OPTIONS
The
.IR locale
utility shall conform to the Base Definitions volume of POSIX.1\(hy2017,
.IR "Section 12.2" ", " "Utility Syntax Guidelines".
.P
The following options shall be supported:
.IP "\fB\-a\fP" 10
Write information about all available public locales. The available
locales shall include
.BR POSIX ,
representing the POSIX locale. The manner in which the implementation
determines what other locales are available is
implementation-defined.
.IP "\fB\-c\fP" 10
Write the names of selected locale categories; see the STDOUT section.
The
.BR \-c
option increases readability when more than one category is selected
(for example, via more than one keyword name or via a category name).
It is valid both with and without the
.BR \-k
option.
.IP "\fB\-k\fP" 10
Write the names and values of selected keywords. The implementation
may omit values for some keywords; see the OPERANDS section.
.IP "\fB\-m\fP" 10
Write names of available charmaps; see the Base Definitions volume of POSIX.1\(hy2017,
.IR "Section 6.1" ", " "Portable Character Set".
.SH OPERANDS
The following operand shall be supported:
.IP "\fIname\fR" 10
The name of a locale category as defined in the Base Definitions volume of POSIX.1\(hy2017,
.IR "Chapter 7" ", " "Locale",
the name of a keyword in a locale category, or the reserved name
.BR charmap .
The named category or keyword shall be selected for output. If a
single
.IR name
represents both a locale category name and a keyword name in the
current locale, the results are unspecified. Otherwise, both category
and keyword names can be specified as
.IR name
operands, in any sequence. It is implementation-defined whether any
keyword values are written for the categories
.IR LC_CTYPE
and
.IR LC_COLLATE .
.SH STDIN
Not used.
.SH "INPUT FILES"
None.
.SH "ENVIRONMENT VARIABLES"
The following environment variables shall affect the execution of
.IR locale :
.IP "\fILANG\fP" 10
Provide a default value for the internationalization variables that are
unset or null. (See the Base Definitions volume of POSIX.1\(hy2017,
.IR "Section 8.2" ", " "Internationalization Variables"
for the precedence of internationalization variables used to determine
the values of locale categories.)
.IP "\fILC_ALL\fP" 10
If set to a non-empty string value, override the values of all the
other internationalization variables.
.IP "\fILC_CTYPE\fP" 10
Determine the locale for the interpretation of sequences of bytes of
text data as characters (for example, single-byte as opposed to
multi-byte characters in arguments and input files).
.IP "\fILC_MESSAGES\fP" 10
.br
Determine the locale that should be used to affect the format and
contents of diagnostic messages written to standard error.
.IP "\fINLSPATH\fP" 10
Determine the location of message catalogs for the processing of
.IR LC_MESSAGES .
.P
The application shall ensure that the
.IR LANG ,
.IR LC_* ,
and
.IR NLSPATH
environment variables specify the current locale environment to be
written out; they shall be used if the
.BR \-a
option is not specified.
.SH "ASYNCHRONOUS EVENTS"
Default.
.SH STDOUT
The
.IR LANG
variable shall be written first using the format:
.sp
.RS 4
.nf

"LANG=%s\en", <\fIvalue\fR>
.fi
.P
.RE
.P
If
.IR LANG
is not set or is an empty string, the value is the empty string.
.P
If
.IR locale
is invoked without any options or operands, the names and values of the
.IR LC_*
environment variables described in this volume of POSIX.1\(hy2017 shall be written to the
standard output, one variable per line, and each line using the
following format. Only those variables set in the environment and not
overridden by
.IR LC_ALL
shall be written using this format:
.sp
.RS 4
.nf

"%s=%s\en", <\fIvariable_name\fR>, <\fIvalue\fR>
.fi
.P
.RE
.P
The names of those
.IR LC_*
variables associated with locale categories defined in this volume of POSIX.1\(hy2017 that are
not set in the environment or are overridden by
.IR LC_ALL
shall be written in the following format:
.sp
.RS 4
.nf

"%s=\e"%s\e"\en", <\fIvariable_name\fR>, <\fIimplied value\fR>
.fi
.P
.RE
.P
The <\fIimplied\ value\fP> shall be the name of the locale that has
been selected for that category by the implementation, based on the
values in
.IR LANG
and
.IR LC_ALL ,
as described in the Base Definitions volume of POSIX.1\(hy2017,
.IR "Chapter 8" ", " "Environment Variables".
.P
The <\fIvalue\fP> and <\fIimplied\ value\fP> shown above shall be
properly quoted for possible later reentry to the shell. The
<\fIvalue\fP> shall not be quoted using double-quotes (so that it can
be distinguished by the user from the <\fIimplied\ value\fP> case,
which always requires double-quotes).
.P
The
.IR LC_ALL
variable shall be written last, using the first format shown above. If
it is not set, it shall be written as:
.sp
.RS 4
.nf

"LC_ALL=\en"
.fi
.P
.RE
.P
If any arguments are specified:
.IP " 1." 4
If the
.BR \-a
option is specified, the names of all the public locales shall be
written, each in the following format:
.RS 4 
.sp
.RS 4
.nf

"%s\en", <\fIlocale\ name\fR>
.fi
.P
.RE
.RE
.IP " 2." 4
If the
.BR \-c
option is specified, the names of all selected categories shall be
written, each in the following format:
.RS 4 
.sp
.RS 4
.nf

"%s\en", <\fIcategory\ name\fR>
.fi
.P
.RE
.P
If keywords are also selected for writing (see following items), the
category name output shall precede the keyword output for that
category.
.P
If the
.BR \-c
option is not specified, the names of the categories shall not be
written; only the keywords, as selected by the <\fIname\fP> operand,
shall be written.
.RE
.IP " 3." 4
If the
.BR \-k
option is specified, the names and values of selected keywords shall be
written. If a value is non-numeric and is not a compound keyword
value, it shall be written in the following format:
.RS 4 
.sp
.RS 4
.nf

"%s=\e"%s\e"\en", <\fIkeyword name\fR>, <\fIkeyword value\fR>
.fi
.P
.RE
.P
If a value is a non-numeric compound keyword value, it shall either be
written in the format:
.sp
.RS 4
.nf

"%s=\e"%s\e"\en", <\fIkeyword name\fR>, <\fIkeyword value\fR>
.fi
.P
.RE
.P
where the <\fIkeyword value\fR> is a single string of values separated by
<semicolon>
characters, or it shall be written in the format:
.sp
.RS 4
.nf

"%s=%s\en", <\fIkeyword name\fR>, <\fIkeyword value\fR>
.fi
.P
.RE
.P
where the <\fIkeyword value\fP> is encoded as a set of strings, each
enclosed in double-quotation-marks, separated by
<semicolon>
characters.
.P
If the keyword was
.BR charmap ,
the name of the charmap (if any) that was specified via the
.IR localedef
.BR \-f
option when the locale was created shall be written, with the word
.BR charmap
as <\fIkeyword\ name\fP>.
.P
If a value is numeric, it shall be written in one of the following
formats:
.sp
.RS 4
.nf

"%s=%d\en", <\fIkeyword name\fR>, <\fIkeyword value\fR>
.P
"%s=%c%o\en", <\fIkeyword name\fR>, <\fIescape character\fR>, <\fIkeyword value\fR>
.P
"%s=%cx%x\en", <\fIkeyword name\fR>, <\fIescape character\fR>, <\fIkeyword value\fR>
.fi
.P
.RE
.P
where the <\fIescape\ character\fP> is that identified by the
.BR escape_char
keyword in the current locale; see the Base Definitions volume of POSIX.1\(hy2017,
.IR "Section 7.3" ", " "Locale Definition".
.P
Compound keyword values (list entries) shall be separated in the output by
<semicolon>
characters. When included in keyword values, the
<semicolon>,
<backslash>,
double-quote, and any control character shall be preceded (escaped)
with the escape character.
.RE
.IP " 4." 4
If the
.BR \-k
option is not specified, selected keyword values shall be written, each
in the following format:
.RS 4 
.sp
.RS 4
.nf

"%s\en", <\fIkeyword value\fR>
.fi
.P
.RE
.P
If the keyword was
.BR charmap ,
the name of the charmap (if any) that was specified via the
.IR localedef
.BR \-f
option when the locale was created shall be written.
.RE
.IP " 5." 4
If the
.BR \-m
option is specified, then a list of all available charmaps shall be
written, each in the format:
.RS 4 
.sp
.RS 4
.nf

"%s\en", <\fIcharmap\fR>
.fi
.P
.RE
.P
where <\fIcharmap\fP> is in a format suitable for use as the
option-argument to the
.IR localedef
.BR \-f
option.
.RE
.SH STDERR
The standard error shall be used only for diagnostic messages.
.SH "OUTPUT FILES"
None.
.SH "EXTENDED DESCRIPTION"
None.
.SH "EXIT STATUS"
The following exit values shall be returned:
.IP "\00" 6
All the requested information was found and output successfully.
.IP >0 6
An error occurred.
.SH "CONSEQUENCES OF ERRORS"
Default.
.LP
.IR "The following sections are informative."
.SH "APPLICATION USAGE"
If the
.IR LANG
environment variable is not set or set to an empty value, or one of the
.IR LC_*
environment variables is set to an unrecognized value, the actual
locales assumed (if any) are implementation-defined as described in the Base Definitions volume of POSIX.1\(hy2017,
.IR "Chapter 8" ", " "Environment Variables".
.P
Implementations are not required to write out the actual values for
keywords in the categories
.IR LC_CTYPE
and
.IR LC_COLLATE ;
however, they must write out the categories (allowing an application to
determine, for example, which character classes are available).
.SH EXAMPLES
In the following examples, the assumption is that locale environment
variables are set as follows:
.sp
.RS 4
.nf

LANG=locale_x
LC_COLLATE=locale_y
.fi
.P
.RE
.P
The command
.IR locale
would result in the following output:
.sp
.RS 4
.nf

LANG=locale_x
LC_CTYPE="locale_x"
LC_COLLATE=locale_y
LC_TIME="locale_x"
LC_NUMERIC="locale_x"
LC_MONETARY="locale_x"
LC_MESSAGES="locale_x"
LC_ALL=
.fi
.P
.RE
.P
The order of presentation of the categories is not specified by this volume of POSIX.1\(hy2017.
.P
The command:
.sp
.RS 4
.nf

LC_ALL=POSIX locale -ck decimal_point
.fi
.P
.RE
.P
would produce:
.sp
.RS 4
.nf

LC_NUMERIC
decimal_point="."
.fi
.P
.RE
.P
The following command shows an application of
.IR locale
to determine whether a user-supplied response is affirmative:
.sp
.RS 4
.nf

printf \(aqPrompt for response: \(aq
read response
if printf "%s\en$response" | grep -- -Eq "$(locale yesexpr)"
then
    affirmative processing goes here
else
    non-affirmative processing goes here
fi
.fi
.P
.RE
.SH RATIONALE
The output for categories
.IR LC_CTYPE
and
.IR LC_COLLATE
has been made implementation-defined because there is a questionable
value in having a shell script receive an entire array of characters.
It is also difficult to return a logical collation description, short
of returning a complete
.IR localedef
source.
.P
The
.BR \-m
option was included to allow applications to query for the existence of
charmaps.
The output is a list of the charmaps (implementation-supplied and
user-supplied, if any) on the system.
.P
The
.BR \-c
option was included for readability when more than one category is
selected (for example, via more than one keyword name or via a category
name). It is valid both with and without the
.BR \-k
option.
.P
The
.BR charmap
keyword, which returns the name of the charmap (if any) that was used
when the current locale was created, was included to allow applications
needing the information to retrieve it.
.P
According to the Base Definitions volume of POSIX.1\(hy2017,
.IR "Section 6.1" ", " "Portable Character Set",
the standard requires that all supported locales must have the same
encoding for
<period>
and
<slash>,
because these two characters are used within the locale-independent
pathname resolution sequence. Therefore, it would be an error if
.IR locale
.BR \-a
listed both ASCII and EBCDIC-based locales, since those two encodings
do not share the same representation for either
<period>
or
<slash>.
Any system that supports both environments would be expected to provide two
POSIX locales, one in either codeset, where only the locales appropriate
to the current environment can be visible at a time. In an XSI-compliant
implementation, the
.IR dd
utility is the only portable means for performing conversions between
the two character sets.
.SH "FUTURE DIRECTIONS"
None.
.SH "SEE ALSO"
.IR "\fIlocaledef\fR\^"
.P
The Base Definitions volume of POSIX.1\(hy2017,
.IR "Section 6.1" ", " "Portable Character Set",
.IR "Chapter 7" ", " "Locale",
.IR "Chapter 8" ", " "Environment Variables",
.IR "Section 12.2" ", " "Utility Syntax Guidelines"
.\"
.SH COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1-2017, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, 2018 Edition,
Copyright (C) 2018 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group.
In the event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online at
http://www.opengroup.org/unix/online.html .
.PP
Any typographical or formatting errors that appear
in this page are most likely
to have been introduced during the conversion of the source files to
man page format. To report such errors, see
https://www.kernel.org/doc/man-pages/reporting_bugs.html .
